<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
    <meta name="description" content="Particle systems.">
    <meta name="cesium-sandcastle-labels" content="Beginner, Showcases">
    <title>Cesium Demo</title>
    <script type="text/javascript" src="../Sandcastle-header.js"></script>
    <script type="text/javascript" src="../../../Build/CesiumUnminified/Cesium.js" nomodule></script>
    <script type="module" src="../load-cesium-es6.js"></script>
</head>
<body class="sandcastle-loading" data-sandcastle-bucket="bucket-requirejs.html">
<style>
    @import url(../templates/bucket.css);

    #toolbar {
        background: rgba(42, 42, 42, 0.8);
        padding: 4px;
        border-radius: 4px;
    }

    #toolbar input {
        vertical-align: middle;
        padding-top: 2px;
        padding-bottom: 2px;
    }

    #toolbar .header {
        font-weight: bold;
    }
</style>
<div id="cesiumContainer" class="fullSize"></div>
<div id="loadingOverlay"><h1>Loading...</h1></div>
<div id="toolbar">
    <table>
        <tbody>
        <tr>
            <td>Rate</td>
            <td>
                <input type="range" min="0.0" max="100.0" step="1" data-bind="value: emissionRate, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: emissionRate">
            </td>
        </tr>

        <tr>
            <td>Size</td>
            <td>
                <input type="range" min="2" max="60.0" step="1" data-bind="value: particleSize, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: particleSize">
            </td>
        </tr>

        <tr>
            <td>Min Life</td>
            <td>
                <input type="range" min="0.1" max="30.0" step="1" data-bind="value: minimumParticleLife, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: minimumParticleLife">
            </td>
        </tr>

        <tr>
            <td>Max Life</td>
            <td>
                <input type="range" min="0.1" max="30.0" step="1" data-bind="value: maximumParticleLife, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: maximumParticleLife">
            </td>
        </tr>

        <tr>
            <td>Min Speed</td>
            <td>
                <input type="range" min="0.0" max="30.0" step="1" data-bind="value: minimumSpeed, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: minimumSpeed">
            </td>
        </tr>

        <tr>
            <td>Max Speed</td>
            <td>
                <input type="range" min="0.0" max="30.0" step="1" data-bind="value: maximumSpeed, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: maximumSpeed">
            </td>
        </tr>

        <tr>
            <td>Start Scale</td>
            <td>
                <input type="range" min="0.0" max="10.0" step="1" data-bind="value: startScale, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: startScale">
            </td>
        </tr>

        <tr>
            <td>End Scale</td>
            <td>
                <input type="range" min="0.0" max="10.0" step="1" data-bind="value: endScale, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: endScale">
            </td>
        </tr>

        <tr>
            <td>Gravity</td>
            <td>
                <input type="range" min="-20.0" max="20.0" step="1" data-bind="value: gravity, valueUpdate: 'input'">
                <input type="text" size="5" data-bind="value: gravity">
            </td>
        </tr>
        </tbody>
    </table>
</div>

<script id="cesium_sandcastle_script">
function startup(Cesium) {
    'use strict';
//Sandcastle_Begin
var viewer = new Cesium.Viewer('cesiumContainer');

//Set the random number seed for consistent results.
Cesium.Math.setRandomNumberSeed(3);

//Set bounds of our simulation time
var start = Cesium.JulianDate.fromDate(new Date(2015, 2, 25, 16));
var stop = Cesium.JulianDate.addSeconds(start, 120, new Cesium.JulianDate());

//Make sure viewer is at the desired time.
viewer.clock.startTime = start.clone();
viewer.clock.stopTime = stop.clone();
viewer.clock.currentTime = start.clone();
viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP; //Loop at the end
viewer.clock.multiplier = 1;
viewer.clock.shouldAnimate = true;

//Set timeline to simulation bounds
viewer.timeline.zoomTo(start, stop);

var viewModel = {
    emissionRate : 5.0,
    gravity : 0.0,
    minimumParticleLife : 1.2,
    maximumParticleLife : 1.2,
    minimumSpeed : 1.0,
    maximumSpeed : 4.0,
    startScale : 1.0,
    endScale : 5.0,
    particleSize : 25.0
};

Cesium.knockout.track(viewModel);
var toolbar = document.getElementById('toolbar');
Cesium.knockout.applyBindings(viewModel, toolbar);

var entityPosition = new Cesium.Cartesian3();
var entityOrientation = new Cesium.Quaternion();
var rotationMatrix = new Cesium.Matrix3();
var modelMatrix = new Cesium.Matrix4();

function computeModelMatrix(entity, time) {
    return entity.computeModelMatrix(time, new Cesium.Matrix4());
}

var emitterModelMatrix = new Cesium.Matrix4();
var translation = new Cesium.Cartesian3();
var rotation = new Cesium.Quaternion();
var hpr = new Cesium.HeadingPitchRoll();
var trs = new Cesium.TranslationRotationScale();

function computeEmitterModelMatrix() {
    hpr = Cesium.HeadingPitchRoll.fromDegrees(0.0, 0.0, 0.0, hpr);
    trs.translation = Cesium.Cartesian3.fromElements(-4.0, 0.0, 1.4, translation);
    trs.rotation = Cesium.Quaternion.fromHeadingPitchRoll(hpr, rotation);

    return Cesium.Matrix4.fromTranslationRotationScale(trs, emitterModelMatrix);
}

var pos1 = Cesium.Cartesian3.fromDegrees(-75.15787310614596, 39.97862668312678);
var pos2 = Cesium.Cartesian3.fromDegrees(-75.1633691390455, 39.95355089912078);
var position = new Cesium.SampledPositionProperty();

position.addSample(start, pos1);
position.addSample(stop, pos2);

var entity = viewer.entities.add({
    availability : new Cesium.TimeIntervalCollection([new Cesium.TimeInterval({
        start : start,
        stop : stop
    })]),
    model : {
        uri : '../../SampleData/models/CesiumMilkTruck/CesiumMilkTruck.glb',
        minimumPixelSize : 64
    },
    viewFrom: new Cesium.Cartesian3(-100.0, 0.0, 100.0),
    position : position,
    orientation : new Cesium.VelocityOrientationProperty(position)
});
viewer.trackedEntity = entity;

var scene = viewer.scene;
var particleSystem = scene.primitives.add(new Cesium.ParticleSystem({
    image : '../../SampleData/smoke.png',

    startColor : Cesium.Color.LIGHTSEAGREEN.withAlpha(0.7),
    endColor : Cesium.Color.WHITE.withAlpha(0.0),

    startScale : viewModel.startScale,
    endScale : viewModel.endScale,

    minimumParticleLife : viewModel.minimumParticleLife,
    maximumParticleLife : viewModel.maximumParticleLife,

    minimumSpeed : viewModel.minimumSpeed,
    maximumSpeed : viewModel.maximumSpeed,

    imageSize : new Cesium.Cartesian2(viewModel.particleSize, viewModel.particleSize),

    emissionRate : viewModel.emissionRate,

    bursts : [
        // these burst will occasionally sync to create a multicolored effect
        new Cesium.ParticleBurst({time : 5.0, minimum : 10, maximum : 100}),
        new Cesium.ParticleBurst({time : 10.0, minimum : 50, maximum : 100}),
        new Cesium.ParticleBurst({time : 15.0, minimum : 200, maximum : 300})
    ],

    lifetime : 16.0,

    emitter : new Cesium.CircleEmitter(2.0),

    emitterModelMatrix : computeEmitterModelMatrix(),

    updateCallback : applyGravity
}));

var gravityScratch = new Cesium.Cartesian3();

function applyGravity(p, dt) {
    // We need to compute a local up vector for each particle in geocentric space.
    var position = p.position;

    Cesium.Cartesian3.normalize(position, gravityScratch);
    Cesium.Cartesian3.multiplyByScalar(gravityScratch, viewModel.gravity * dt, gravityScratch);

    p.velocity = Cesium.Cartesian3.add(p.velocity, gravityScratch, p.velocity);
}

viewer.scene.preUpdate.addEventListener(function(scene, time) {
    particleSystem.modelMatrix = computeModelMatrix(entity, time);

    // Account for any changes to the emitter model matrix.
    particleSystem.emitterModelMatrix = computeEmitterModelMatrix();

    // Spin the emitter if enabled.
    if (viewModel.spin) {
        viewModel.heading += 1.0;
        viewModel.pitch += 1.0;
        viewModel.roll += 1.0;
    }
});

Cesium.knockout.getObservable(viewModel, 'emissionRate').subscribe(
    function(newValue) {
        particleSystem.emissionRate = parseFloat(newValue);
    }
);

Cesium.knockout.getObservable(viewModel, 'particleSize').subscribe(
    function(newValue) {
        var particleSize = parseFloat(newValue);
        particleSystem.minimumImageSize.x = particleSize;
        particleSystem.minimumImageSize.y = particleSize;
        particleSystem.maximumImageSize.x = particleSize;
        particleSystem.maximumImageSize.y = particleSize;
    }
);

Cesium.knockout.getObservable(viewModel, 'minimumParticleLife').subscribe(
    function(newValue) {
        particleSystem.minimumParticleLife = parseFloat(newValue);
    }
);

Cesium.knockout.getObservable(viewModel, 'maximumParticleLife').subscribe(
    function(newValue) {
        particleSystem.maximumParticleLife = parseFloat(newValue);
    }
);

Cesium.knockout.getObservable(viewModel, 'minimumSpeed').subscribe(
    function(newValue) {
        particleSystem.minimumSpeed = parseFloat(newValue);
    }
);

Cesium.knockout.getObservable(viewModel, 'maximumSpeed').subscribe(
    function(newValue) {
        particleSystem.maximumSpeed = parseFloat(newValue);
    }
);

Cesium.knockout.getObservable(viewModel, 'startScale').subscribe(
    function(newValue) {
        particleSystem.startScale = parseFloat(newValue);
    }
);

Cesium.knockout.getObservable(viewModel, 'endScale').subscribe(
    function(newValue) {
        particleSystem.endScale = parseFloat(newValue);
    }
);

var options = [{
    text : 'Circle Emitter',
    onselect : function() {
        particleSystem.emitter = new Cesium.CircleEmitter(2.0);
    }
}, {
    text : 'Sphere Emitter',
    onselect : function() {
        particleSystem.emitter = new Cesium.SphereEmitter(2.5);
    }
}, {
    text : 'Cone Emitter',
    onselect : function() {
        particleSystem.emitter = new Cesium.ConeEmitter(Cesium.Math.toRadians(45.0));
    }
}, {
    text : 'Box Emitter',
    onselect : function() {
        particleSystem.emitter = new Cesium.BoxEmitter(new Cesium.Cartesian3(10.0, 10.0, 10.0));
    }
}];

Sandcastle.addToolbarMenu(options);
        //Sandcastle_End
    Sandcastle.finishedLoading();
}
if (typeof Cesium !== 'undefined') {
    window.startupCalled = true;
    startup(Cesium);
}
</script>
</body>
</html>
